For a year from September 2005, under the nose of the Panthéon’s unsuspecting security officials, a group of intrepid “illegal restorers” set up a secret workshop and lounge in a cavity under the building’s famous dome. Under the supervision of group member Jean-Baptiste Viot, a professional clockmaker, they pieced apart and repaired the antique clock that had been left to rust in the building since the 1960s. Only when their clandestine revamp of the elaborate timepiece had been completed did they reveal themselves.”When we had finished the repairs, we had a big debate on whether we should let the Panthéon’s officials know or not,” said Lazar Klausmann, a spokesperson for the Untergunther. “We decided to tell them in the end so that they would know to wind the clock up so it would still work.